1. Field of the Invention
This Integrated Bi-modal Wheel Assembly (IBMWA), invention relates generally to freight transport and mass transport of humans by roadway and railway. The transport of humans and freight on railways is a well established form of surface transportation, and is performed by a broad set of railway vehicles that are engineered, designed and manufactured to operate exclusively on steel railway tracks—the most common being the Standard Gauge (56.5 in. between inside rail flanges) parallel steel railway infrastructure common throughout North America. The transport of humans and freight on roadways is also a well established form of surface transportation, and is performed by a variety of roadway vehicles that are engineered, designed and manufactured to operate exclusively on many classes of improved roadways.
More specifically, this invention relates to integrated assemblies of custom roadway wheels and custom lightweight railway wheels. This unique combination of custom roadway wheels and pneumatic tire assemblies, when integrated with custom lightweight railway wheels; are both coupled and concentrically assembled on a common axle with special provisions for the automatic inflation and deflation of the roadway pneumatic tire. In addition to freight and mass transit systems, other applications for use include dual (civilian—military) use and other single-purpose transport systems (e.g., ordnance, bio, chemical, nuclear, mixed or hazardous waste).
There exists throughout the transportation industry several different adaptive apparatuses that are designed to convert roadway vehicles so they may be placed onto railways and transport in a railway mode. Conversely, there exists, to a lesser extent, different adaptive apparatuses that are designed to convert railway vehicles so they may be placed onto roadways and transport in a roadway mode. These existing apparatuses are operational throughout the transportation industry and are all independent assemblies and mechanisms that are attached to primary vehicles as auxiliary devices.
All of these referenced devices are relatively complex and bulky, and function by moving or extending an auxiliary set of wheels to engage and facilitate one particular mode of transport, or to retract to an inoperative or stored position thereby allowing the vehicle to transition back to its primary mode of transport.
The existing auxiliary apparatuses all function on a set of axles and wheels that are separate and independent from the vehicles primary set wheels and axles, and in many designs, the auxiliary wheels are significantly smaller in diameter than the vehicles primary wheels. The smaller wheels have the disadvantage of substantially slowing and diminishing the vehicle's ability to transport at regulated speed limits.
Many of the existing auxiliary apparatuses also require modifications and/or provisions to railway and roadway infrastructures for supporting a vehicle's transition and alignment to and from the railway and roadway transport modes. These existing auxiliary apparatuses while stored in a retracted and non-functioning position on a vehicle while operating in a roadway transport mode are particularly cumbersome and reduce the vehicles maneuverability and driveability.
2. Related Art
For many years specially constructed devices have been designed, patented and used to adapt road vehicles for use on railroad tracks. It is not uncommon to see a standard pickup truck making its way along a railroad track under its own power. Generally such adaptations are made to support railroad service and maintenance operations. Typically, the road vehicle is driven in a conventional fashion to the selected point at which it is to begin using the railroad track. After positioning the road vehicle over the rails, the rail engagement apparatus is actuated such that the rail wheels are lowered from the vehicle to the track. This process may simultaneously raise the vehicle's front road wheels to eliminate their contact of the road wheels with both the rails and the track bed. Alternatively the front road wheels are raised in a separate mechanical operation. The rear road wheels usually remain in contact with the rails or the track bed to provide the needed propulsion. When the road vehicle is to be returned to normal road usage, the process described above is reversed.
As in the above description, all of the known designs incorporate separate road wheel and rail wheel pairs which may be raised or lowered depending on the desired transport mode, (i.e., road or rail). Some of these designs incorporate the mechanism for raising and lowering the road-rail wheels in the basic design of thew vehicle. Others provide a separate wheel assembly or “bogie” which mates with the chassis of the vehicle to adapt it to the alternate transport mode. A few of the known and relevant examples representative of the above approaches are presented in the following:
Madison (U.S. Pat. No. 5,186,109) teaches an adaptation device having railroad wheels that attach to a frame of a road vehicle. This device has a side shift capability whereby the railroad wheels may be lowered to engage the rails when the road vehicle is offset sideways and parallel to the tracks. An automatic system centers the vehicle over the tracks after the rail wheels have engaged the rails. A spring arrangement is also provided to maintain the rail wheels in contact with the rails. In two subsequent patents, (U.S. Pat. No. 5,619,931) and (U.S. Pat. No. 5,868,078), Madison provides truck tractor vehicle frames for adaptation for rail use. These frames also enable the tractor to be used on a roadway. Each patent incorporates a front guide rail wheel unit and a rear road wheel drive unit. When the front unit is lowered the rail wheels engage the truck's rails. When the front unit is raised, separately mounted road wheels engage the roadway. When the rear unit is lowered its road wheels are in contact with the roadway. Raising the rear unit allows a separately mounted rear rail wheel bogey to engage the rails.
Bush (U.S. Pat. No. 5,740,742) has adapted a truck tractor for use on railways to tow one or more railcars while retaining the capability to tow highway trailers. Bush provides a set of hydraulically retractable railway wheels to guide the rear drive wheels while on the rails. The front of the tractor is equipped with a set of retractable railway wheels that are used to lift the front steering axle of the truck tractor clear of the railroad rails.
Kershaw (U.S. Pat. No. 6,021,719) has invented a self-propelled track vehicle capable of traveling at highway speeds and traveling by rail. This is accomplished by providing separate sets of road and rail wheels, all of which may be selectively raised and lowered to enable the desired operating mode. Kershaw also provides a turntable device attached to the vehicle's chassis so that it may be rotated 90 degrees for placement on the railway track.
Pyle (U.S. Pat. No. 6,199,485) provides a rail conversion module for a tractor that allows the tractor to be driven either on the ground or on the railroad tracks. He provides a hinged frame module that fits under the tractor with front rail wheels and driven rear rail wheels. Both wheel sets may be raised for ground travel or lowered for rail travel.
Nugent (U.S. Pat. No. 1,853,572) has invented a combination railway wheel, and roadway pneumatic tire and wheel that incorrectly assumes a pneumatic tire with metallic structural reinforcing changes diameter as a function of increases or decreases in tire pressure. This patent does not provide for the automatic inflation and deflation of the pneumatic tire and does not position the pneumatic tire adjacent to and in contact with the railway wheel to provide for assisting wheel alignment with the steel track while operating in the railway transport mode.
Strauss (U.S. Pat. No. 2,193,046) has an automotive train invention that principally addresses a centrally located motor-generator truck assembly and the distribution of motive power there from. The invention features transit cars that ride on, and are supported on pneumatic tires.
The weight-bearing pneumatic tires are intended to ride on a roadway surface that is adjacent to and at the same level as a set of rail tracks. The invention includes a retractable set of small diameter rail wheels on separate axles that provide for aligning and steering the vehicle on the railway, but with no capacity for carrying the vehicle's load.
Zakula, Van Gorp (U.S. Pat. No. 6,158,602) has adapted large mobile gantry cranes to increase the cranes load-carrying capacity by the addition of special railway wheels adjacent to and concentric with the crane's standard roadway tires and wheels. The additional railway wheels are configured with double flanges and are designed to function exclusively on short sections of straight track that are installed onto, and therefore elevated above the roadway surface. These surface-mounted tracks are typically installed in heavy industrial shipyards and freight handling terminals. This invention has no intention or purpose for inflating or deflating the gantry crane tires, but merely applies the special railway wheels to increase the crane's load carrying capacity and avoid the potential for overloading and crushing the pneumatic tires.
Forster (U.S. Pat. No. 4,596,192) has adapted a system for passenger transportation using a vehicle of various configurations based on a system of building blocks. The vehicles are to be assembled for roadway transportation only, railway transportation only, or with the provisions for both roadway and railway transportation by the same vehicle. All vehicles of the invention are to be equipped with pneumatic tires on horizontal axles to carry the total vertical weight and load the vehicle. The vehicles of the Forster invention intended for railway transportation are additionally equipped with sets of small diameter pneumatic wheels that rotate about a vertical axis and function to ride on vertical curb-walls of a special infrastructure and to carry the lateral loads of a railcab when the vehicle is executing turns or curves. The invention refers to these curb-walls as rails, but they are not remotely similar to the steel flange rails common to the North American rail transportation infrastructure. The special curb-wall infrastructures of the invention are presently installed in a very few international urban metropolitan areas and have thus far proven very costly to construct and maintain. The invention, other than falling in the broad realm of transportation systems, is not related in any way, shape of form to the Integrated Bi-Modal Wheel Assembly invention of this patent application.
Pollitt (U.S. Pat. No. GB2280644A) has invented a vehicle for carrying freight or passengers and is adaptable for travel on roadways, railways and waterways. The invention primarily addresses the broad scope of a system and means for transporting passengers and freight on roadways, railways and waterways with no specific definition on how the various subsystems and components of the vehicle will function structurally, mechanically, electrically or dynamically. The invention drawings indicate the closely coupled assembly of a roadway wheel and a railway wheel which is not described in the text of claims. The railcab invention addresses an “alternative support medium or media” required for the railcab to be lifted onto or off of the railway. The railcab invention addresses “wheels of very elastic material” that, paradoxically, suggests the capability of supporting the railcab such that the rail wheels are raised free and clear of the roadway surface, and yet will compress sufficiently to lower the railway wheels to contact and rest on the railway tracks. The invention does not address any provision for a way or means whatsoever for the “wheels of very elastic material” to be pneumatically inflated or deflated to provide for the physical raising or lowering of the railcab, which without such provision, the stated function of modal convertibility is physically impossible.
None of the patents cited above either address or provide apparatuses in the form of the Integrated Bi-modal Wheel Assembly of this invention, and that is designed to enable vehicles equipped with said Integrated Bi-modal Wheel Assemblies to physically transition to and from the railway transport modes and the roadway transport modes without changes in vehicles configuration, and without requiring any changes or modifications to existing North American railway and roadway infrastructures.
As can be readily concluded from the above discussion, this wide assortment of conversion and adaptation devices are complicated by their need to incorporate raising and lowering mechanisms or to provide a separate undercarriage to allow for the second transportation mode. This complexity adds fabrication costs, increases vehicle weight and maintenance, reduces reliability and may adversely impact operational safety. Such systems are also complex to operate, particularly when making roadway-railway transitions.
With the advent of freight and mass transit systems incorporating road-rail adaptive vehicles, a critical need exists for new methods for reliably and efficiently transitioning from a roadway or railway transportation mode to the other mode. To provide a seamless transition, the vehicle must be liberated from the cumbersome and complex equipment and processes as taught in the prior art.
Thus it is a primary objective of this invention to provide wheel assemblies for road-rail vehicles that will efficiently, effectively and safely function on either a roadway or a rail way. It is a further objective of this invention that this assembly may not require any actuation mechanisms to accomplish the roadway/railway transition. It is yet a further objective of this invention that the roadway/railway transition may be accomplished automatically without operator intervention. It is a final objective of this invention to provide a wheel assembly that is lightweight yet structurally sound for the intended dual use, roadway/railway application.